Exhaust concealing and silencing device



April 1945- N: o. COLLIER. JR 2,372,765

EXHAUST CONCEALING AND SILENCING DEVICE Filed Dec. 14, 1945 3 Sheets-Sheet l W If I; WW

April 3, 1945. N. o. COLLIER. JR

EXHAUST CONCEALING AND SILENCING DEVICE Filed Dec. 14, 1945 3 Sheets-Sheet 2 I 11 van tor W I tamey April 3,1945- N. o. COLLIER, JR

EXHAUST CONCEALING AND SILENGING DEVICE Filed Dec. 14, 1943 3 Sheets-Sheet 3 Inventor y M MOW.

a Attarneys line 3-3 of Figure Patented Apr. 3, 1945 EXHAUST CON CEALING AND SILEN GIN G DEVICE Nolan 0. Collier, Jr., Montgomery,

Ala., assignor of one-half to Nolan Oliver Collier, Sr., Montgomery, Ala.

Application December 14, 1943, Serial No. 514,266

Claims. This invention relates to an improved device for concealing and silencing the flaming exhaust gases discharged from the cylinders of a radial internal combustion engine such as is commonly used for driving the propellers of aircraft.

An important object of the present invention is to provide a device of the above kind which is particularly adapted for use in connection with aircraft, and by means of which the exhaust gases are finally discharged in a smooth, quiet stream some distance rearwardly of the aircraft propeller after the flame and much .of the pressure of the exhaust gases have been spent, thereby eliminating much of the noise and disturbance of airflow that accompanies the conventional discharge of exhaust gases outwardly into the wash of an aircraft propeller.

A specific feature of the present invention is the provision of a casing surrounding the engine and the associated exhaust concealing and silencing device, and by means of which air is directed into contact with theouter surfaces of the various parts of the device for cooling purposes.

A further specific object of the present invention is to provide a device of the above kind which is simple and compact in construction. efiicient in operation, and otherwise well adapted for meeting the requirements for a successful commercial use.

The present invention consists in the novel form, combination and arrangement of parts hereinafter more fully described. shown in the accompanying drawings and claimed.

In the drawings, wherein like reference characters indicate corresponding parts throughout the several views:

Figure 1 is a view partly in elevation and partly in central longitudinal section, showing an exhaust concealing and silencing device associated with the propeller-driving engine of an airraft.

Figure 2 is an enlarged fragmentary central longitudinal sectional view showing the major portion of the exhaust concealing and silencing device per se with the casing broken away and the engine omitted.

Figure 3 is a transverse sectional view taken on Figure 4 is an enlarged fragmentary detail 'section taken on the plane of line 44 of Figure 2.

Figure 5 is an elevation of the vaned disc initially impinged by the exhaust gases when discharged into the housing of the exhaust concealing and silencing device proper.

Figure 6 is a fragmentary end elevation looking at the rear end of the device shown in Figure 1.

, I8 set at a slight directly in front of the Figure '7 is a. fragmentary section taken on line 77 of Figure 1,

Figure 8 is a fragmentary section taken on line 8-8 of Figure 2.

Figure 9 is an enlarged sectional detail view, partly broken away, showing the manner .of mounting and spacing the impellers on the shaft of the present device.

Figure 10 is a transverse section taken on line |Ul0 of Figure 2.

Figure 11 is an enlarged fragmentary sectional view, showing details of the yieldable props and braces.

Referring in detail to the drawings, 5 indicates a conventional type of radial internal combustion engine having a forwardly extending drive shaft 6 which carries the usual aircraft propeller, not shown. In accordance with the present invention, each radial cylinder of the engine 5 is provided with a rearwardly extending exhaust pipe I, and the rear ends of these exhaust pipe l are inturned where they connect and communicate with a vertical annular exhaust manifold B having a circular series of radial inwardly extending discharge pipes 9 whose inner ends are directed rearwardly in adjacent concentric relation to an axial shaft I 0, as indicated at I i. A circular protecting plate or fire wall 12 is vertically disposed manifold 8 and is therethe latter and the engine forward passage of the fore interposed between 5 so as to prevent any flaming exhaust toward the engine, as it is discharged from the pipes 9. This plate or wall I2 is provided with a series of peripheral notches,

as at i3, to receive the exhaust pipes T and aid' in effectively mounting said plate or wall 12 in, position.

The present device further includes an elongated cylindrical housing 14 whose forward open end is disposed in close proximity to the discharge ends it of pipes 9 and is provided with an outturned annular flange 15 whose inner portion is offset, as at 16. The shaft I0 is disposed axially of and extends rearwardly nearly through the housing 14, and secured on this shaft I0 and arranged within the offset portion l6 of the flange I5 is a vaned disc I 1 whose major central portion is provided with a. number of radial vanes angle, as clearly shown in Figure 4. Thus, the exhaust gases which discharge from the pipes 9 will act upon the blades l8 so as to rotate the disc 11 and become initially broken up by the latter. A series of screw impellers l9 are disposed along the length of the shaft l0 within the housing l4, the same bein spaced uniformly wardly, they successively impinge upon the impellers 19 for being retardedand broken up, and extending axially from the rear end of the hous ing I4 is a discharge pipe 22 from which the exhaust gases finally discharge in a steady relatively quiet stream, free of flame and with the blast pressure thereof substantially spent. If desired, the housing It may be provided with forwardly and downwardly extending air intake 23 and similar lateral air intakes 23a for the admission of cool air diagonally of the housing If for retarding and cooling purposes. Also, an auxiliary exhaust discharge pipe 24 may extend upwardly and rearwardly from the housing ll near its rear end portion. Any slightly flaming exhaust gases discharging from this pipe 24 will not be readily seen from the ground by an observer directly below the aircraft.

Disposed in spaced concentric relation to and surrounding the engine 5, exhaust pipes l, manifold 8, casing l4 and discharge pipe 22 is an outer casing 25 of circular cross section and taperin gradually smaller rearwardly. The rear end of the casing 25 has a central opening through which the rear end of the pipe 22 extends, and the front end of said casing 25 is substantially open. 'Also, adjacent its front end, the casing 25 is provided with any desired number of louveredair inlets 25 and at its rear end with louvered vents or air outlets 21. Thus, a flow of cool air may enter and pass through the casing 25 so as to contact the outer surfaces of the parts enclosed therein for cooling purposes with respect tosaid parts. The

rearward passage of cool air is also permitted by' louvered air passages in the fire wall or plate 12,

as at 28. Suitable means is provided for sustaining the casing 25 in proper spaced relation to the housing ll, such as yieldable radial props 29 between the casing 25 and the discharge pipe 22 and radial braces 30 between the under side of the housing H and the bottom portion of the casing 25. The props 30 are also of. similar yielding construction so that shocks may be cushioned between the parts and 25. Each prop 29' and brace includes a rod r having a plunger 0: movable in a cylinder b and backed by a compression spring 0 disposed in the cylinder. It will be noted that the pipes 23, 23a and 24 project outwardly through the casing 25, and any suitable means is provided for journaling the shaft l0 axially of the housing H including a bearing bracket 3| associated with the rear end of said shaft and affixed to the housing H. v

In operation, the exhaust gases pass from the cylinders of the engine 5- through the exhaust pipes I into the manifold 8, whereupon said gases are discharged rearwardly from the radial pipes 9 into the housing l4. These exhaust gases discharging from the pipes 9 initially impinge the vaned disc I! for being initially retarded and broken up, and this retarding and breaking down operation is repeated as the gases flow rearwardly and successively impinge the impellers IS. The exhaust gases finally discharge from the rear end of the pipe 22 in a flameless condition and in a smooth relatively quiet stream which does not interfere with the wash of the aircraft propeller driven by the shaft 6. Additional discharge of exhaust gases is bad through the pipe 24 and retarding and cooling action upon the gases is effected by means of the cool air admitted through the pipes 23 and 220. Further, the various parts I, 8, ll, 22 and 24 are effectively cooled by means of the air admitted into and flowing through the casing 25 into contact with the outer surfaces ofthose parts.

From the foregoing description, it is believed that the construction and operation, as well as the advantages of the present invention will be readily understood and appreciated by those skilled in the art. Minor changes in the details of construction illustrated and described are contemplated within the spirit and scope of the invention as claimed. I

What is claimed as new is:

1. In combination with the propeller-driving radial-type internal combustion engine of an aircraft having rearwardly extending exhaust pipes, a vertical annular exhaust manifold disposed rearwardlyvof said engine and communicating at equally spaced points directly with the outlet ends of said exhaust pipes, said manifold having'a circular series of equally spaced and inwardly extendingradial discharge pipes provided with rearwardly directed inner ends, an elongated cylindrical housing disposed rearwardly of said manifold coaxially of the latter so that said radial discharge pipes discharge into the forward end thereof, a shaft disposed axially of said housing, the inner ends of said discharge pipes being grouped about said shaft, a varied disc carried by said shaftat the front end of said housing to be initially impinged by the exhaust gases discharged from said radial discharge pipes, a series of screw impellers mounted on said shaft in spaced relation longitudinally of the latter, and a straight final exhaust pipe extending axially of and rearwardly from said housing, and an outer casing surrounding the engine, the manifold and the housing, said outer casing having a front air inlet and a rear air outlet for permitting flow of cooling air therethrough.

2. In combination with the propeller-driving radial-type internal combustion engine of an aircraft, a. vertical annular exhaust manifold disposed rearwardly of saidengine and communicating with the exhaust pipes of the cylinders of said engine, said manifold having a circular series of inwardly extending radial discharge pipes provided with rearwardly directed inner ends, an

- elongated cylindrical housing disposed rearwardly of said manifold coaxially of the latter so that said radial discharge pipes discharge into the forward end thereof, a shaft disposed axially of said housing, a vaned disc carried by said shaft at the front end of said housing to be initially impinged by the exhaust' gases discharged from said radial discharge pipes, a series of impellers mounted on said shaft in spaced relation longitudinally of the latter, and a final exhaust pipe extending axially of and rearwardly from said housing, an outer casing disposed in concentric relation to and surrounding the engine, the manifold, the housing and the final exhaust pipe, said outer casing having air inlets and outlets respectively near the front and the rear thereof for permitting the rearward flow of cooling air into contact with the outer surfaces of said manifold, housing and exhaust pipe.

3. In combination with the propeller-driving rad al-type internal combustion engine of an aircraft, a vertical annular exhaust manifold disposed rearwardly of said engine and communieating with the exhaust pipes of the cylinders of said engine, said manifold having a circular series of inwardly extending radial discharge pipes provided with rearwardly directed inner ends, an elongated cylindrical housing disposed rearwardly oi said manifold coaxially of the latter so that said radial discharge pipes discharge into the forward end thereof, a shaft disposed axially of said housing, a vaned disc carried by said shaft at the front end of said housing to be initially impinged by the exhaust gases discharged from said radial discharge pipes, a series of impellers mounted on said shaft in spaced relation longitudinally of the latter, and a final exhaust pipe extending axially of and rearwardly from said housing, an outer casing disposed in concentric relation to and surrounding the engine, the manifold, the housing and the final exhaust pipe, said outer casing having air inlets and outlets respectively near the front and the rear thereof for permitting the rearward flow of cooling air into contact with the outer surfaces of said manifold, housing and exhaust pipe, 9. forwardly and downwardly extending air inlet for said housing projecting outwardly through said outer casing, and an upwardly and rearwardly extending aux.- iliary exhaust discharge pipe extending from the rear portion of said housing outwardly through said outer casing.

-4. In combination with the propeller-driving radial-type internal combustion engine of an aircraft, a vertical annular exhaust manifold disposed rearwardly of said engine and communicating with the exhaust pipes of the cylinders of said engine, said manifold having a circular series of inwardly extending radial discharge pipes provided with rearwardly directed inner ends, an elongated cylindrical housing disposed rearwardly of said manifold coaxially of the latter so that said radial discharge pipes discharge into the forward end thereof, a shaft disposed axially of said housing, a vaned disc carried by said shaft at the front end of said housing to be initially impinged by the exhaust gases discharged from said radial discharge pipes, a series of impellers mounted on said shaft in spaced relation longitudinally of the latter, and a finalexhaust pipe extending axially of and rearwardly from said housing, an outer casing disposed in concentric relation to and surrounding the engine, the manifold, the housing and the final exhaust pipe, said outer casing having air inlets and outlets respectively near the front and the rear thereof for permitting the rearward flow of cooling air into contact with the outer surfaces of said manifold, housing and exhaust pipe, and

radially yielding braces and props for sustaining the housing and the outer casing in spaced concentric relation. i

5. In'cornbination with the propeller-driving radial-type internal combustion engine of an aircraft, a vertical annular exhaust manifold disposed rearwardly of said engine and communicating with the exhaust pipes of the cylinders of said engine, said manifold having a circular series of inwardly extending radial discharge pipes provided with rearwardly directed inner ends, an elongated cylindrical housing disposed rearwardly of said manifold coaxially of the latter so that said radial discharge pipes discharge into the forward end thereof, a shaft disposed axially of said housing, a vaned disc carried by said shaft at the front end of said housing to be initially impinged by the exhaust gases discharged from said radial discharge pipes, a series of impellers mounted on said shaft in spaced re lation longitudinally of the latter, and a final exhaust pipe extending axially of and rearwardly from said housing, an outer casing disposed in concentric relation to and surrounding the engine, the manifold, the housing and the final exhaust pipe, said outer casing having air inlets and outlets respectively near the front and the rear thereof for permitting the rearward flow of cooling air into contact with the outer surfaces of said manifold, housing and exhaust pipe. and a fire wall interposed between the engine and said annular manifold in close proximity to and in front of the latter, said fire wall having a series of peripheral notches receiving the exhaust pipes from the cylinders of said engine.

NOLAN' O. COLLIER, JR. 

